Is it bad for me to skip withdrawal bleeds on the pill?

For many women, their monthly period can be inconvenient, can cause mood swings, and may result in pain. For this reason, it is extremely understandable that there is often a temptation to try and avoid having periods at all, if you are using the oral contraceptive pill.

The oral contraceptive pill is a form of hormonal contraception, which can be split into two main categories, the combined oral contraceptive pill (COC), and the progesterone only pill (POP or mini pill).

When it comes to skipping withdrawal bleeds, the advice is only applicable to users of the COC, as the POP works differently, as detailed below.

Which pill do you use?

The pill you use will fit into one of the main two main pill types above, the COC or the POP. There are many different types of pill in each group.

As suggested by its name, the POP only contains one hormone, progesterone. It is taken every day routinely, and without a break. It works by using several different actions, including stopping ovulation from occurring in most women who take it. It also alters the lining of the womb and the cervical mucus, making it a much more hostile environment to sperm should an egg still be released. As a result, sperm are less likely to reach an egg, minimising the chances of pregnancy.

Because the POP is taken continuously, many women do not have periods while taking it, or they may have irregular, light periods when small amounts of lining are shed.

The COC contains two hormones, progesterone and oestrogen. Traditionally, when taking COCs, a woman takes 21 tablets and then has a seven day pill free break, during which she has her period. Some types of COC have seven dummy pills in each pack to be taken during the pill free break to make it easier to remember when to start the next pack.

The main mechanism of action of the COC is to stop ovulation from taking place. It does this by inhibiting a surge of two other hormones, FSH and LH. The combined pill also affects cervical mucus and makes the lining of the womb unsuitable for an egg to implant.

When taken in the traditional way, the 7-day pill break then causes a drop in oestrogen and progesterone levels, resulting in the lining of the womb (endometrium) breaking down. This results in a period.

The COC was originally designed in this way by manufacturers so that it mimicked a woman’s natural menstrual cycle. However, guidance now advises that taking it in this way does not make it any more effective than if it were taken continuously. While taking the COC, the oestrogen component causes the lining of the womb to thicken and grow, while the progesterone component prevents it thickening excessively.

Continuous pill taking – skipping withdrawal bleeds

It is important to be aware that only certain formulations of combined oral contraceptives are suitable for continuous use. COCs can be divided into low oestrogen (ethinylestradiol) and standard strength preparations. Only the standard strength, monophasic preparations are suitable for continuous pill taking, or a process known as tricyling. Example of these pill types include Microgynon 30®; Ovranette®; Rigevidon®; and Marvelon.

Low oestrogen preparations are still frequently prescribed because some women find that they produce fewer side effects. However, they still need to be taken in the traditional way (21 days of taking, followed by a seven day break) to avoid frequent breakthrough bleeding. Low oestrogen preparations include Loestrin 20®, Ethinylestradiol 20, Mercilon®, and a number of others as well. It’s not necessarily bad for you to skip withdrawal bleeds on this type of pill, but it’s not a good idea because it nearly always leads to breakthrough bleeding, so defeats the point.

Monophasic and biphasic combined pill

To make things even more confusing, combined pills are further divided into monophasic COCs and phasic COCs. Monophasic COCs are combined pills in which the amount of oestrogen and progesterone in each active tablet is the same through the cycle. This is the pill type that is most commonly used.

Phasic COCs are preparations in which the amount of oestrogen and progesterone in the tablets varies over the cycle. The packet may contain two or three or even four different sets of active pills. Phasic COCs are not suitable for extended or continuous pill use, so you definitely shouldn’t try and take packets back to back, and should only take them as per instructions.1

Tricycling

This means taking three packets of the pill one after the other without a break, and then taking a four day pill free break after the 3rd pack. During this time most women would expect to have a period. The COCP would then be restarted after a 4-day break and three more packs taken back to back before having another break. Typically, this would result in a women having five periods a year instead of the usual 13.

Tricycling is the method that many doctors now recommend.2 This is partly because no one really enjoys periods, and that it means less money spent on sanitary products, and also tricycling has been shown to decrease problems with PMT and period pain.

Most women that do this will have very few side effects, although some may experience a small amount of breakthrough bleeding and may feel better just running two packs together. A woman following this method should expect to be protected against pregnancy in the same way as if she were using the traditional pill taking method of 21 days of tablets followed by a pill free break.

However, It is worth speaking to your doctor for more advice and to ensure it is suitable to follow this method with the specific pill you take.

Continuous (tailored) pill taking

Continuous taking of the COC means it is taken daily with no break at all. Many women find that they experience breakthrough bleeding after a few cycles if they do this, but some are lucky and do not. Breakthrough bleeding usually occurs when the endometrial lining has thickened a bit too much, so starts to break down.

Should breakthrough bleeding occur, current advice is for a woman to stop taking the pill for four days (and throw those four days of pills away so you remain on the right day of the pill pack), and to restart taking the pill after that four day break.

During those four days, a woman would expect to continue to bleed. This should enable the womb lining to thin sufficiently to stop the breakthrough bleeding and restore the balance.3

If breakthrough bleeding (spotting) is something that happens regularly, some women find they prefer to plan for it by introducing a four day break every few pill packs, similar to the theory behind tricycling. Again, as long as the break is only four days, the pill remains as effective at preventing pregnancy as it is believed you can technically ovulate after a break of four days. The jury is out on whether or not a four day break is better than a seven day break if you are taking breaks between every single pill pack.

Is it safe?

Some women who consider continuous pill taking it may be concerned about whether or not it is a safe thing to do. Reassuringly, there is little to suggest it has any more risks than the traditional method of pill-taking. In fact, many other commonly used forms of contraception are continuous by default.

The main difference, however, been other continuous use contraceptives and the constant use of the COC is that other forms of continuous contraception are progesterone only contraceptives, such as the POP and the depot injection. The progesterone on its own thins the uterine lining, meaning that often your periods may stop altogether.

With the COC, the lining of the womb is not thinned initially, it is just kept in balance by the oestrogen and progesterone, making a woman more likely to still have some periods when the lining thickens too far. However, over time and more prolonged continuous use of the COC, the lining does start to thin in a similar way to what occurs with the POP, meaning periods may simply not be required. As such, over time, women who use the COC may be able to use it continuously with increased success.

It is also suggested that premenstrual symptoms such as bloating and irritability may also be less with continuous COC use.4

Does taking the pill continuously still protect against pregnancy?

In short, yes it does. If you stop your bleed while taking a standard strength, non-phasic combined oral contraceptive pill, you will be protected from pregnancy at the same level of efficacy (effectiveness) as if you were taking the combined pill traditionally.

It is important to remember that if you do have a pill break due to bleeding that the pill must be restarted after four days, which is enough time to shed excess lining but not enough time to gear up to ovulate.5

Do I need to see my doctor before using the pill to stop my periods?

It is advisable to see your doctor before altering your pill taking regime. This is especially the case if you are unsure whether you are taking a standard strength or a low dose oestrogen preparation, and to discuss whether this is the best option for you.

Jennifer is a General Practitioner, medical writer, parent, and founder of the Grace Kelly Ladybird Trust, registered charity for childhood cancer awareness and research (www.gracekellyladybird.co.uk). She also has a particular interest in women’s and children’s health, and enjoys medical writing, particularly helping make medical information easily accessible to those who want to find out more.